Phosphorus compounds



United States Patent Ofiice 3,011,000 Patented Nov. 28, 1961 No.813,327. Divided and this appiication May 20, 1960, Ser. No. 30,446

4 Claims. (Cl. 260-6665) This invention relates to novel phosphoruscompounds. More particularly, it relates to novel ethylenicallyunsaturated secondary phosphine compounds. This application is adivision of patent application S.N. 813,327, filed May 15, 1959, nowabandoned.

The technology of phosphorus polymers has heretofore remained relativelyundeveloped. However, phosphorus polymers are growing increasinglyattractive for use in specialized applications wherein their novelproperties may be advantageously utilized.

it is an object of this invention to provide novel phosphorus compounds.

Another object is the provision of novel secondary phosphine compoundscontaining ethylenic unsaturation and a process for their manufacture.

A further object is the provision of a new class of polymerizablephosphorus monomers.

These and other objects are attained by reacting substantially equimolarproportions of an alkali metal salt of a primary organophosphine and anethylenically unsaturated organic halide as hereinafter describedin asubstantially oxygen-free reaction system wherein at least one of thereactants is dissolved in an inert solvent.

The following examples are given in illustration of the invention andare not intended as limitations thereon. Where parts are mentionedthey'are parts by weight.

Example I Thirteen parts (about 0.1 mol) of sodio-phenylphosphine areslurried in 75 ml. of absolute ether in a stirred reactor equipped witha reflux condenser. The mixture is placed under a nitrogen atmosphereand a solution of 11 parts (about 0.1 mol) of Z-chloroethyl vinyl etherdissolved in 50 ml. of absolute ether is slowly charged to the reactor.The reaction is started at about room temperature, but the heat ofreaction raises the temperature of the reaction system to reflux (circa35 C.) and the ether is distilled oii, using an external source of heatto drive off any residual ether present after the reaction ceases. Theremaining fluid is vacuum distilled to purify the product which is acolorless liquid containing about 17.3% of combined phosphorus byWeight. Infrared analysis reveals absorption characteristic of ethylenicunsaturation as well as of ether linkages and of phosphorusphenyl andphosphorus-hydrogen linkages, indicating the product to be2-(phenylphosphino)ethyl vinyl ether.

Example 11 Ten parts (about 0.1 mol) of lithio-secondarybutylphosphineare slurried in 50 ml. of toluene in a stirred reactor. This mixture isplaced under a nitrogen atmosphere and a solution of 16 parts (about 0.1mol) of 4- chloro-n-butyl isopropenyl ether dissolved in 75 ml. oftoluene is slowly charged to the reactor. The reaction is started atabout room temperature, but the heat of reaction raises the temperatureof the reaction system to about 50 C. After all of the 4-chloro-n-butylisopropenyl ether solution has ben charged, the toluene is removed bydistillation under a nitrogen atmosphere. The remaining fluid is vacuumdistilled to purify the product which is a liquid containing about 14.9%of combined phosphorus by Weight. Infrared analysis reveals absorptioncharacteristic of ethylenic unsaturation as well as ofphosphorus-hydrogen and of ether linkages, indicating the product to be4-(secondarybutylphosphino)-nbutyl isopropenyl ether.

The ethylenically unsaturated organic halides employed in the practiceof this invention are omega-halogenatedalkyl-vinylidene etherscorresponding to the general formula:

In this formula, 11 is an integer of from 16, X is either bromine,chlorine or iodine and each R may be, independently, either a hydrogen,a methyl or a phenyl radical. I

Therefore, the 2-chlorothyl vinyl ether and the 4- chloro-n-butylisopropenyl ether employed in the examples may be replaced, for example,with one of the following omega-halogenated-alkyl-vinylidene others withequivalent results: vinyl others such as chloromethyl vinyl ether,2-bromoethyl vinyl ether, 3-cl1loro-n-prop'yl vinyl ether,4-iodo-n-butyl vinyl ether, S-bromo-n-pen'tyl vinyl ether,6-chloro-n-hexyl vinyl ether, l-chloroethyl vinyl ether,2-bromo-isopropyl vinyl ether, phenyl-bromm methyl vinyl ether,l-chlortr-l-phenyl-methyl vinyl ether, l-methyl-Z-bromo-ethyl vinylether, 2-chloro-n-propyl vinyl ether, 2-bromo-2-phenyl-ethyl vinylether, 2-methyl- 3-chloro-n-propyl vinyl ether, 4-bromo-4-phenyl-n-butylvinyl ether, 2,4-dimethyl-4-chloro-n-pcntyl vinyl ether, etc.isopropenyl ethers such as bromomethyl isopropenyl ether, 2-chl0roethylisopropenyl ether, 3-iodon-propyl isopropenyl ether, 4-bromo-n-butylisopropenyl ether, 5- chloro-n-pentyl isopropenyl ether, 6-iodo-n-hexylisopropenyl ether, l-bromoethyl isopropenyl ether, 2-chloro-isopropylisopropenyl ether, 1-phenyl-3-chloro-n-propyl isopropenyl ether,2,3-dimethyl-4 bromo-n-buty1 isopropenyl ether,1-phenyl-3,5-dimethyl-6-chloro-n-hexyl isopropenyl ether, etc.; andstyryl others such as chloromethyl alphaphenylvinyl ether, 2-bromoethylalpha-phenylvinyl ether, 3-iodo-n-propyl alpha-phenylvinyl ether,4-br0mo-n-butyl alphaphenylvinyl ether, 5-iodo-n-pentylalpha-phenylvinyl ether, 6-chloron-hexyl alpha-phenylvinyl ether,l-phenyl- 2-chloroethyl alpha-phenylvinyl ether, l-chlo-ro-isopropylalpha-phenylvinyl ether, 3-methyl-4-brgmo-n-pentyl alpha-phenylvinylether, etc. i

The alkali metal salts of primary ogranophosphines employed in thepractice of this invention correspond to the general formula: p

H R-I M" R is a hydrocarbon radical containing from. 1-12 carbon atoms.M is an alkali metal radical, i.e., either a lithium, sodium, potassium,cesium or a rubidium radical. Therefore, in place of thesodio-phenylphosphine and lithiosecondarybutylphosphine employed in theexamples may be substituted, for example, rubidio-ethylphosphine,sodio-ethylphosphine, sodio-isopropylphosphine, potassioandlithio-n-butylphosphine, potassio-n-pentylphosphine, lithio nhexylphosphine, potassio n heptylphosphine, sodio-isooctylphosphine,potassio-decylphosphine, cesiododecylphosphine,sodio-cyclohexylphosphine, etc. with similar results. Such salts arereadily prepared by reacting substantially equimolar proportions of thealkali metal and the appropriate primary or-ganophosphine in a highlypolar but inert solvent, e.g., liquid ammonia or sulfur dioxide, underan inert atmosphere. This type of synthesis is described in greaterdetail by C. H. S. Hitchcock and F. G. Mann in the Journal of ChemicalSociety, June 1958, (429), pp. 2081-2086.

The unsaturated secondary phosphine compounds comactants.

a 3 prising the subject of this general formula:

R R1 H-1 (1)nOC I-=CH2 wherein R and R are radicals as heretoforedisclosed.

These compounds are prepared by reacting substantiallyequimolar'proportions of an'alkali metal salt of a primaryorgano-phosphine and an ethylenically unsaturated organic halide, of theclass heretofore disclosed, under an inert, e.g., nitrogen, atmosphere.The reaction is eifected in the presence of a solvent inert to the re-Suitable solvents include, for example, hydrocarbons such as benzene,toluene, xylene, hexane, cycloheXane, etc. or polar solvents such asether, dioxane, tetrahydrofuran, liquid ammonia, liquid sulfur dioxide,etc. It is not necessary that both reactants be soluble in the solventemployed. However, it is preferred to employ a polar solvent, or amixture of solvents, inwhich both reactants are soluble. The reactiontemperature employed is usually dictated by practical requirements sincethe reaction proceeds efiiciently at all temperatures. When liquidammonia or sulfur dioxide are employed as the solvent, sub-zerotemperatures below the bolting points of such are generally required.Super-atmospheric pressures may optionally be employed to raise theboiling point of the solvent employed.

The final reaction mixture is comprised of the desired ethylenicallyunsaturated secondary phosphine in admixture with solvent andresidualreactants. Precipitated metal halide is also present. Recovery oftheproduct is accomplished according to conventional techniques. The

precipitated salt may be removed by, e.g., filtration or decantation.The solvent and residual reactants may be removed, for example, bydistillation, either under vacuum orunder an inert atmosphere. Theethylenically unsaturated secondary phosphines so produced are generallyfluids. However, those of higher molecular weight, especially thosecontaining two or more phenyl groups, may be crystalline or waxy solids.

These ethylenically unsaturated secondary phosphines are useful asantioxidants for incorporation into such resinous compositions as e.g.,synthetic or natural rubber, styrene or substituted styrene polymers,vinyl ester polymers such as polyvinyl chloride, polyvinyl. acetate,

etc, acrylic polymers such as polyacrylonitrile, polymethylmethacrylate,etc. They may also be polymerized to form linear polyphosphines whichare generally flameresistant resins useful as flameproofing agents forpaper, textiles, wood, etc. Such resins may also be molded, extruded orcast as sheets, films, tubing, etc. for, e.g., electrical insulation,fire barriers, surface coatings, etc.

Example III temperature. The resulting solid material is dissolved in150 ml. of a 1:1 by weight mixture of acetone and benzene, whichsolution is then poured into an excess of absolute ether to precipitatethe polymer. A hard, clear,

invention correspond to the H glass-like polymer containing about 17.3%phosphorus by weight is obtained in about 95% yield. This polymer issoluble in acetone and methanol. Upon testing for flammability byholding the polymer in the flame of a Meeker burner until it ignites,the polymer is found to be self-extinguishing.

Example IV A rectangular chip of ponderosa pine measuring about I A X1"X 3" is immersed for 4 hours in ml. of a 50% by weight solution of the2-(phenylphosphino)- ethyl vinyl ether polymer obtained in Example IIIdissolved in benzene. The pine chip is then heated in an air oven at 80C. for about 3 hours to remove all adsorbed solvent. Testing forflammability by holding the pine chip vertically in the flame of aMeeker burner until it ignites, the chip is found to beself-extinguishing.

It is obvious that many variations may be made in the products andprocesses set forth above without departing from the spirit and scope ofthis invention.

What is claimed is:

1. An ethylenically unsaturated secondary phosphine corresponding to thegeneral formula:

wherein n is an integer of from 1 to 6, R is a hydrocarbon radicalcontaining from 1 to 12 carbon atoms and each R is a radicalindependently selected from the group consisting of hydrogen, methyl andphenyl radicals.

2. 2-(phenylphosphino)ethyl vinyl ether.

-3. 4-(secondarybutylphosphino) n butyl isopropenyl ether.

4. A process for preparing an ethylenically unsaturated secondaryphosphine corresponding to the general formula:

which comprises reacting substantially equirnolar proportions of analkali metal salt of a primary organophosphine corresponding to thegeneral formula:

t RP-M and an ethylenically unsaturated organic halide corresponding tothe general formula:

in a substantially oxygen-free reaction system with at least one of thereactants dissolved in an inert solvent; wherein, in each of the aboveformulae, M is an alkali metal radical, X is a halogen radical of thegroup consisting of bromine, chlorine and iodine, n is an integer offrom 1 to 6, R is a hydrocarbon radical containing from 1 to 12 carbonatoms and each R is a radical independently selected from the groupconsisting of hydrogen, methyl and phenyl radicals.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 S OIIOOO November 28,, 1961v Albert Ya Garner It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column I line 68 for "hen" read been -5 oolurnn 2 line l7 for"2-chlorothyl" read 2-ch1or0fathyl line 47,, for "ogranophosphines" readorganophosphines a Signed and sealedfthis 1st day of May 1962,

(SEAL) Attest:

ERNEST we SWIDER D VID L. LADD Attesting Officer v Commissioner ofPatents

1. AN ETHYLENICALLY UNSATURATED SECONDARY PHOSPHINE CORRESPONDING TO THEGENERAL FORMULA: